Decision-making is a complex process requiring the integration of both current sensory information about the world and stored knowledge about environmental contingencies. Recently, neurophysiologists have begun to identify neural activity in higher order sensory and motor brain regions that correlates with decision formation. In the lateral intraparietal area (LIP), neurons encode decision variables such as expected reward magnitude, outcome probability, and subjective desirability of choices during a visuomotor task; this information is neither sensory nor motor but guides effective decision-making. Decision studies to date, however, have ignored information about time, a crucial element of choice behavior: real world decisions occur between choices with different outcomes at different times. The goal of the proposed research is to develop a psychophysical test to quantify primate choice behavior in time, and employ this task to explore how such temporal information is represented in the activity of decision-related neurons in LIP. This research seeks to explore both the neural basis of choice in time as well as the integration of temporal information into decision processes.